Research in microbiology最新文献

Cutibacterium acnes is a commensal Gram-positive anaerobic bacterium that can also act as an opportunistic pathogen in various diseases, particularly in prosthetic joint infections (PJI). Throughout this review, we delve into the current understanding of the intricate interactions between C. acnes and host cells and discuss bacterial persistence in the host. C. acnes colonization and subsequent PJI set-up represent complex processes involving bacterial adhesion, immune recognition, and host response mechanisms. We highlight existing knowledge and gaps in specific host-pathogen interactions and stress the importance of acquiring additional information to develop targeted strategies for preventing and treating C. acnes-related PIJ.

This review explores the diverse applications of Bacillus thuringiensis (Bt) beyond its traditional role as a bioinsecticide. Bt produces a variety of compounds with distinct chemical structures and biological activities. These include antimicrobial agents effective against plant pathogens and bioactive compounds that promote plant growth through the production of siderophores, hormones, and enzymes. Additionally, Bt's industrial potential is highlighted, encompassing biofuel production, bioplastics, nanoparticle synthesis, food preservation, anticancer therapies, and heavy metal bioremediation. This critical analysis emphasizes recent advancements and applications, providing insights into Bt's role in sustainable agriculture, biotechnology, and environmental management.

Pseudomonas sp. AW4 is a highly arsenic (As) resistant bacterium with plant growth promoting properties, originally isolated from the soybean (Glycine max L.) rhizosphere. In order to safely use this isolate in diverse bioformulations, its characterization needs to be completed and a reliable identification must be provided. In the present work, we analyzed the morpho-physiological, biochemical and genomic characteristics of Pseudomonas sp. AW4. Identification of the isolate varied according to the parameters analyzed, mainly biochemical and physiological tests or individual genes and phylogenetic analyses. In this regard, we performed massive sequencing of its genome, in order to consistently complete its characterization and identification. Pseudomonas sp. AW4 formed a monophyletic clade with P. urmiensis SWRI10, presenting 3.08 % of unique genes against this reference isolate. More than 70 % of AW4 genes were also shared with P. oryziphila strain 1257 NZ and with P. reidholzensis strain CCOS 865. The search for genes related to As resistance evidenced the presence of the operon arsHRBC. Taken together, results of the present work allow identification of this bacterium as Pseudomonas urmiensis AW4 and open up a number of opportunities to study this strain and understand the mechanisms of arsenic resistance and plant growth promotion.

The article presents an analysis of the history of the microbiology course delivered during the inaugural operational year of the Institut Pasteur in Paris. The year 1889 is examined through the lens of three hitherto unknown volumes that bring together the microbiology lectures delivered at the end of the 19th century. The course was entirely independent from the teaching provided by the universities or faculties of medicine and rapidly gained international recognition. Indeed, the course provided the students with the theoretical knowledge of Pasteurian theories regarding the completely new discipline of microbiology and the specific techniques used to cultivate, conserve, and observe microbes. The steady increase in the number of lectures between 1889 and 1914 reflects the expansion of microbiological knowledge during this period. The contributions of researchers such as Émile Roux (1853-1933), Élie Metchnikoff (1845-1916), and Amédée Borrel (1867-1936) illuminated the collaboration and the growing diversification of expertise at the heart of the Institut Pasteur (IP). Furthermore, this study highlights the international influence of the course, as evidenced by the participation of foreign students. It examines the history of the course as a powerful tool for disseminating knowledge of new microbiological techniques and the results of research carried out in Pasteur's laboratories. It also examines how the course served as a political instrument, asserting the authority of the Institut Pasteur in the field of microbiology in France and extending its influence worldwide.

Research on microbial biofilms has primarily concentrated on bacterial-bacterial and bacterial-fungal interactions, leaving fungal-fungal dynamics underexplored. The present study examines interactions within dual-species fungal biofilms, with a particular emphasis on Candida albicans. The behavior and pathogenicity of this yeast are significantly influenced by its interactions with other fungal species in biofilms, where its ability to shift between yeast and hyphal forms contributes significantly to biofilm formation. These fungal species biofilms exhibit a complex interplay of synergistic cooperation and antagonistic competition, depending on the environmental context and resource availability. Understanding these interactions is essential for advancing our knowledge of fungal biofilm.

Tailocins are nano-scale phage tail-like protein complexes that can mediate antagonistic interactions between closely related bacterial species. While the capacity to produce R-type tailocin was found widely across Gammaproteobacteria, the production of F-type tailocins seems comparatively rare. In this study, we examined the freshwater isolate, Pragia fontium 24613, which can produce both R- and F-type tailocins. We investigated their inhibition spectrum, focusing on clinically relevant enterobacteria, and identified the associated tailocin gene cluster. Transmission electron microscopy confirmed that inactivation of the tape measure protein within the tailocin cluster disrupted R-tailocin production. Comparative analysis of Budviciaceae gene clusters showed high conservation of R-type tailocin genes, whereas F-type tailocin genes were found in only a few species, with little conservation. Our findings indicate a high prevalence of bacteriocin production among underexplored Enterobacteriales species. Detected tailocins showed potential as antimicrobials targeting clinically significant pathogens.

Translation initiation for 5'-UTR contributes primarily to the efficient protein expression in Escherichia coli. Many studies have focused on constructing random 5'-UTR libraries to investigate the impact of mRNA features on protein translation efficiency. However, the study on the effect of the absence of specific types of nucleotides in the entire 5'-UTR region on translation efficiency has not yet been reported. Here, we constructed four reporter plasmid libraries encoding the sfGFP fluorescent protein, each preceded by 5'-UTRs that lack one specific nucleotide (25B, 25D, 25H, 25V). Each library was transformed into E. coli cells, and the fluorescence distribution among the different libraries was analyzed by flow cytometer. Additionally, we quantified the activity of 256 unique 5'-UTR sequences and analyzed the impact of the corresponding mRNA sequence features on translation efficiency. We found that the 25D library, which lacks the C nucleotide, exhibited the highest overall translation efficiency compared to the other three libraries. Moreover, the minimum free energy and 16S rRNA hybridization energy of the 5'-UTR sequence could work coordinately to influence translation efficiency. The 5'-UTR sequences lacking the C nucleotide also achieve efficient protein translation. These findings may provide several guiding principles for precisely tuning protein expression.

Antibiotic resistance poses a global crisis fuelled by widespread antibiotic use, particularly against Gram-negative bacteria like Klebsiella pneumoniae, a leading cause of hospital-acquired infections with high mortality rates. Urgent identification of effective drug targets is imperative, with a focus on metabolic pathways to inhibit bacterial growth. Targeting the crucial metabolic pathways of K. pneumoniae would be a more efficient way to prevent its growth and the diseases that it causes. The present study focused on inhibiting the UDP-N-acetylglucosamine--N-acetylmuramyl-(pentapeptide)pyrophosphoryl-undecaprenol N-acetylglucosamine transferase (MurG) enzyme, which is a key enzyme in peptidoglycan biosynthesis pathway. A high throughput virtual screening was used to find possible lead molecules from Enamine -High-Throughput Screening Center library. The resulting high binding affinity ligands were further assessed for their drug-likeness and other pharmacokinetic properties. Based on these analyses, the three ligands Z95813755_1, Z324718246_1 and Z324718246_2 were selected for further molecular dynamic simulation studies. The molecular dynamic simulation results and MM/PBSA analysis predicted that both Z95813755_1 and Z324718246_2, molecules show higher binding affinity towards MurG. For the first time we are reporting potential candidate inhibitors against MurG from K. pneumoniae, providing new insights in management of multi drug resistant K. pneumoniae infections.